The invention relates to surgical instruments, and more particularly, to instruments used for clamping bones.
The sesamoid bones are a pair of accessory bones located under the first metatarsal head of each foot. They are typically oval in shape and are invested in the tendons of the flexor hallucis brevis muscle. In certain cases, the resection of a sesamoid bone or sesamoidectomy may be undertaken. Access to the lateral sesamoid bone is typically from the dorsal side of the foot and through the first interspace between the first and second metatarsals. The approach is a vertical, top to bottom approach in the sagittal plane and difficulty many times occurs in manipulating instruments for resection due to the limited space available between the first and second metatarsals.
In a prior technique, a stab incision is made between the sesamoid bone and the metatarsal head. At this time, the sesamoid bone is not clamped. The incision is then extended proximally and distally. A thumb and forefinger forceps is then used to grasp the conjoined tendon of Adductor Hallucis and the sesamoid bone is peeled from it by use of a scalpel. The sesamoid bone is then removed with the forceps. Problems have arisen with this method in that the sesamoid bone tends to rotate away from the scalpel and consequently, the chances of inadvertent cutting of the Flexor Hallucis Longus tendon and other surrounding tissues are increased.
In another prior technique, a clamp is used to engage the distal and proximal ends of the sesamoid bone. The engaged clamp is used to position the sesamoid bone during use of the scalpel and is used to remove the resected sesamoid bone. The clamp has two arms which pivot in relation to each other and has hooks formed at the ends of the arms which are used to engage the ends of the sesamoid bone. Because of its configuration and the angle at which it is applied, this clamp has been found to interfere with certain surgical operations involved in the sesamoidectomy. Performance of some surgical operations at an awkward angle results. Additionally, since the clamp must be large enough to reach the ends of the sesamoid bone and since it remains engaged with the bone during its removal, the size of the incision may be increased to accommodate the clamp. This increased incision size has been found to be undesirable. Another disadvantage of this type of clamp is the tenuous grip it provides on the sesamoid bone which is generally oval shaped and is slippery during surgery. In using this prior technique clamp which grips the ends of the sesamoid bone, slippage of the bone out of the clamp has been experienced during removal of the resected bone.
It would be useful to be able to clamp the sesamoid bone during certain uses of the scalpel in a sesamoidectomy so that it does not rotate away or otherwise move except as desired. This would provide greater control and decrease the chances of inadvertent cutting of surrounding tissues. Various surgical clamps, such as those described above, have been used for sesamoidectomies, however, such clamps have had disadvantages. It would be a valuable contribution to the art to provide a clamp which, when used in a sesamoidectomy or similar type of operation, would be applied through a plane perpendicular to the incision plane so that interference with surgical operations is lessened. It would also be valuable to provide a clamp which does not require a larger incision to be made and which provides a more positive grip on the clamped object.